We plan to conduct some pilot experiments to collect the low resolution reflections on one (or more, depending on time) crystal forms of the bacterial RuvB DNA helicase. The helicase forms a hexameric ring with 32 point group symmetry and a number of crystal forms have substantial non-crystallographic symmetry. We hope to try to use some of the phasing techniques that use very low resolution reflections in combination with non-crystallographic symmetry averaging. The results of the data collection at SSRL will be used in combination with phasing models that will either be generated based on measurements of the dimensions of the helicase ring from electron microscopy or from electron microscopy of the crystals themselves in collaboration with Dr. Mark Yeager at The Scripps Research Institute.